48V Direct-to-PoL modules support data centre set-ups

Efficient, dense, cost-effective and reliable power distribution is a critical element in data centres and other distributed electronics applications, such as autonomous driving vehicles and LED lighting. But CPU power conversions has customarily relied on 12V distribution, even though it requires the bus to carry four times the current carried by a 48V bus, not to mention that the power lost in a 12V bus can be as much as 16 times the loss in a 48V bus.

The benefits of a higher distribution bus voltage, particularly 48V, are well known that even Internet giant Google has recently announced its initiative to promote 48V server and distribution infrastructure as a standard for data centres.

"By developing its 48V server infrastructure, Google pioneered green data centres. And by promoting an open 48V rack standard, Google is now enabling a reduction in the global cloud electricity footprint," said Vicor CEO Patrizio Vinciarelli.

Among the latest generation of high distribution bus voltage are Vicor Corporation's 48V Direct-to PoL (Point-of-Load) power components, which enable system designers to implement green distributed system solutions with high conversion efficiency, high power density and low distribution loss in a fraction of the space.

Vicor's latest generation 48V Direct-to-PoL modules include the Cool-Power PI3751-02 Buck-Boost, Pre-Regulator Module (PRM) and the VTM48Kp020x Current Multiplier Module (VTM). The PRM receives its input from a 48V distributed bus (Vin up to 55V) and drives a controlled "factorised" bus voltage to the VTM; the VTM generates an output voltage that is 1/24th of the voltage at its input while multiplying by 24X the current delivered to the CPU. Current multiplication by as much as 48X at the PoL delivers higher efficiency, density and bandwidth, which are the distinguishing attributes of factorised power.

In applications that require telemetry and digital control, a Vicor PI3020 Digital Control and Telemetry device may be used with a VTM/PRM pair. Among the features of the PI3020 are PMBus^[a] and SVID control interfaces with full support for server processor power VR13, and backwards compatibility for VR12.5 and VR12.0 designs.

PRM delivers up to 240W at 98 per cent efficiency by utilising a MHz ZVS Buck-Boost topology in a 10mm x 14mm LGA package. The VTM's MHz ZVS/ZCS Sine Amplitude Converter (SAC) delivers up to 95A of continuous current, and up to 190A of peak current, at 95 per cent peak efficiency in a moulded 13mm x 23mm ChiP package with greater than 400A/in² current density.

The VTM features very low output impedance, allowing users to remove bulk capacitors from the PoL. Furthermore, only the high current VTM needs to be close to the CPU; the PRM can be located remotely. And, whereas conventional buck regulator solutions require enough phases to handle the full transient current demanded by a CPU operating in turbo or boost mode, the VTM's own Turbo Mode delivers up to twice its rated continuous current for up to 10ms, thereby accommodating transient CPU operating modes without sacrificing system power density and cost.

Vicor has pioneered 48V direct-to-PoL power conversion. These latest generation products expand a family of VTM and PRM modules that have exhibited substantial improvements in each generation. Over the past decade, Vicor has, in fact, reduced converter power loss by an average of 25 per cent every two years while increasing power density. Compared to solutions using traditional "multi-phase" buck regulators, Factorised Power offers superior efficiency, density, transient response and noise performance. A third party study has recently demonstrated that the VTM's noise spectrum is an order of magnitude lower than legacy multi-phase buck regulators.

In addition to its Factorized Power families of PRMs and VTMs, Vicor's portfolio of 48V input PoL products encompasses an ecosystem of regulating converters, such as its PI35xx family of Cool-Power ZVS Buck Regulators, suitable for powering a wide variety of loads, and auxiliary power rails, directly from a 48V bus. In any power system application–from distributed to centralised–Vicor's families of modular DC-DC and AC-DC power components, and its "no surprises" Power Component Design Methodology and online PowerBench tools, enable power systems engineers to rapidly configure and implement complete systems offering field proven reliability and predictability and industry-leading performance, density, efficiency and economy.